In general, as shown in FIG. 1, an ammunition includes a case 1 with a front mouth and a rear base, a bullet 3 fitted to the front mouth of the case 1, a propellant 5 charged into the case 1 and a primer 7 installed in the rear base of the case 1.
In this ammunition, if a percussion lock applies an impact to the primer 7, the propellant 5 is exploded by the application of impact. At this moment, the bullet 3 is pushed forwards by the explosive power of the propellant 5. As a result, the bullet 3 is shot forwards with a high propelling force. The bullet 3 thus shot flies far away and reaches a target point.
With this conventional ammunition, the bullet 3 is configured to have a planar rear portion so that it can receive the explosive power of the propellant 5 as much as possible. This poses a drawback in that, when the bullet 3 is shot into the air, an eddy air flow is generated in the planar rear portion of the bullet 3. This imparts increased air resistance to the bullet 3, consequently reducing the movement velocity of the bullet 3 and shortening the shooting range thereof.
Due to the eddy air flow generated in the planar rear portion of the bullet 3, the conventional ammunition suffers from reduction in the straight-ahead movement ability of the bullet 3. This leads to a problem in that the deviation between an aiming point and a hitting point becomes greater, thus reducing the target hitting rate of the bullet 3.